Behavior of nuclear projectile fragments produced in collisions of 14. 5 A GeV sup 28 Si with Pb and Cu targets

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.43.835· OSTI ID:5907285

Price, P B; He, Y D ^[1]

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1. Department of Physics, University of California, Berkeley, California 94720 (US)

Using CR-39 nuclear track detectors and an automated scanning system, we have studied the behavior of projectile fragments with charges 8{le}{ital Z}{sub {ital F}}{le}13 produced in interactions of 14.5{ital A} GeV {sup 28}Si nuclei with Pb and Cu targets. Both nuclear and electromagnetic spallation contribute to fragmentation of beam nuclei in Pb and Cu. The total charge-changing cross sections of nuclear projectile fragments with 9{le}{ital Z}{sub {ital F}}{le}13 interacting in Pb are found to be enhanced by 10 to 30 % relative to charge-changing cross sections of stable nuclides. The enhancement occurs primarily in interactions with large loss of charge. In Cu the charge-changing cross sections of secondaries show no significant excess. The mean free path of secondary fragments shows no dependence on the distance from the point of origin. This result rules out at 95% confidence level the production of nuclear fragments with interaction cross sections enhanced by a large factor as conjectured by some workers, but the result is consistent with a two-component model in which {similar to}30% of secondary beams are off-stability isotopes with total cross sections enhanced by {similar to}25%. Our measurements of angular distributions of projectile fragments showed that the transverse momentum distributions are similar to those measured at (1--2){ital A} GeV. The charge pickup cross section of 14.5{ital A} GeV Si is measured to be 0.07--1.3 mb in Pb and {le}0.9 mb in Cu, which is of the same order of magnitude as that measured at {similar to}1{ital A} GeV.

• OSTI ID: 5907285
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 43:2; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
ANGULAR DISTRIBUTION
BROOKHAVEN AGS
CHARGED-PARTICLE REACTIONS
COPPER
CROSS SECTIONS
CYCLIC ACCELERATORS
DIRECT REACTIONS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
GEV RANGE
GEV RANGE 100-1000
HEAVY ION REACTIONS
IMPACT PARAMETER
LEAD
LINEAR MOMENTUM
MEAN FREE PATH
METALS
NUCLEAR FRAGMENTATION
NUCLEAR REACTIONS
PICKUP REACTIONS
SILICON 28 REACTIONS
SPALLATION
SYNCHROTRONS
TRANSFER REACTIONS
TRANSITION ELEMENTS
TRANSVERSE MOMENTUM